Generally, touchpad systems are implemented for a variety of applications. Some of these applications include, computer interfaces, keypads, keyboards, and other applications. Various types of touch pads are known. Optical touch pads have certain advantages over some other types of touch pads at least for some applications. Various types of optical touchpad systems may be used in some or all of these applications. However, conventional optical touchpad systems may include various drawbacks.
For example, conventional optical touchpad systems may be costly, imprecise, bulky, temperamental, fragile, energy inefficient, or may have other weaknesses and/or drawbacks. Further, conventional systems may only be able to detect position of an object (e.g., a fingertip, a palm, a stylus, etc.) when the object is engaged with the touchpad. This may limit the position-detection of optical touchpad systems to detecting the position of the object in the plane of the surface of the touchpad.
While other conventional systems may determine the position of the object in three-dimensions, these systems may include a waveguide that forms a touchpad surface and rely on photosensitive elements positioned on a side of the waveguide opposite from the touchpad surface. From the radiation that passes from the object and completely transverses the waveguide to be received on the opposite side of the waveguide by the photosensitive elements, three-dimensional position information related to the object may be determined. However, these configurations require that the photosensitive elements be dispersed throughout the touchpad underneath the waveguide. This may increase the bulk of the touchpad, decrease a ruggedness of the touchpad, decrease an efficiency of the touchpad, limit the applications for which the touchpad is feasible, and/or include other drawbacks and/or limitations.
These and other limitations of conventional touchpad systems may restrict the types of applications for which touchpad systems may be employed as human/machine interfaces. Various other drawbacks exist with known touchpads, including optical touchpads.